Field of the Invention
This invention relates to inspection systems for small, at least partially rotationally symmetric, cylindrical objects, such as stents. More particularly, a mandrel is configured for the inspection and identification of the objects.
Description of the Related Art
Current automated inspection systems such as the FineScan® and Sierra™ systems from Visicon Technologies Inc., (Napa, Calif.) are well known in the stent industry for providing machine assisted dimensional and visual defect inspection of stents. These systems rely on a translucent mandrel that provides a bright contrast background as the stent is rotated in front of a line scan camera to build up a line-by-line unrolled image of the stent. While these systems provide fast and reliable inspection, physically loading the stents on the mandrels is time consuming and requires a high degree of manual dexterity as the mandrels are not easily mounted and dismounted from the system on their own. Further, these mandrels are somewhat expensive and fragile. So an automatic method of loading and unloading such an inspection machine would be desired.
Systems for inspecting stents and measuring dimensions of stents are disclosed in U.S. Pat. No. 6,879,403, “Three Dimensional Scanning Camera” by Freifeld, U.S. Pat. No. 7,020,324, “Precision measurement of Tube Wall Thickness,” by Freifeld and U.S. Pat. No. 7,619,646, “System and Method to Illuminate the Inside Diameter of a Stent,” by Freifeld et al. All three of U.S. Pat. Nos. 6,879,403; 7,020,324 and 7,619,646 are incorporated by reference in their entireties herein.
It is also important to relate the inspection results for a given stent to its manufacturing conditions such as which location in a polishing machine it occupied. Currently, manual systems of tagging the stent with information related to prior manufacturing steps are employed so any automated handling system must also provide a means to provide single part traceability. As with any manual operation in a medical device production the potential exists for a human to choose the wrong mandrel for the given inspection. If would be preferred if this was failsafe in an automatic handling approach.
There remains a need for systems and components for the inspection and identification of stents and other cylindrical objects that does not have the limitations of the prior art methods.